For the attainment of a high starting speed with limited energy consumption, the jackets of such shells are often made of a material of lower specific weight, usually aluminum, while the core consists usually of tungsten.
It has been found that conventional shells of this type are relatively ineffectual against stacked targets, i.e. a plurality of plates disposed one behind the other. In spin-stabilized shells, for example, a forward portion of the shell core is consumed (i.e. smashed) upon the penetration of the first plate. The spin drives the core fragments apart so that they are no longer effective against the following plate.
Fin-stabilized anti-tank impact shells of elongate shape have no spin or only a very slight so-called equalization spin. The latter is so small that it does not cause the above-described disadvantageous effect with stacked-plate targets. These projectiles are therefore fairly effective against such targets, provided that the impact angles are relatively steep.
During the passage of such shell through a stacked-plate target at a flat angle, however, the rod-shaped shell bends in the forward plate. As a result, the shell fragments scatter in the following plates and do not impinge close to one another at a point of the main armor, thus losing some of their power. The destruction of the shell is due to a deflection from its path during penetration of an armor plate at a large angle to the plate normal.